Split pulley



(N6 Model.)

6 J.- E. DONOVAN.

SPLIT PULLEY.

No. 593,646. Patented Nov. 16,1897.

W Q LQAFVWUWWJ Witnesses 4 Inventor 1 I W. %%L S. Q Attorney *N TED STATES PATENT Prion,

SPLIT PU LLEY.

SPECIFICATION forming part of Letters Patent No. 593,646, dated November 16, 1897.

Original application filed April 17, 1895, Serial No. 546,161. Divided and this application filed A ril 26, 1897. Serial No.

' 633,840- (No model.)

Figure 1 is a face elevation of a split pulley exemplifying my invention; Fig. 2, a perspective view of one of the halves of the pulley Fig. 3, a side elevation of one of the bushings; Fig. 4, a perspective view of the pair of bushings belonging in a single pulley, one half of one of these bushings being, however, omitted and the two halves of the other bushing being, shown as abnormally separated;

and Fig. 5, a vertical transverse section of one of the bushings in conjunction with a shaft.

In the drawings, 1 indicates the rim of the pulley; 2, the hub; 3, the j oint-cracks between the two halves of the rim, the rim being cast integrally and subsequently broken in two;

4, a pair of ribs extending across the inner face of the rim at each of the joint-cracks, these ribs forming between them a V-shaped groove whose root is in the plane of the jointcrack; 5, lugs projecting inwardly from the rim of the pulley, there being eight of these lugs arranged in pairs, a pair near each edge of the rim and straddling the joint-cracks, the lugs standing some distance apart; 6, bolts passing through the pairs of lugs and serving to unite the pulley-halves at the rim; 7 bosses formed uponthe inner faces oflugs 5 and surrounding the bolts 6, these bossesbeing coned to form an angular groove where they make contact with each other, it being understood that the two bosses of each pair are cast integrally and subsequently cracked when the pulley is to be parted; 8, boltinglugs-projecting outwardly from the periphery of the hub and disposed in pairs, one pair at each end of the hub and straddling the jointoracks therein, it being understood that the hub, as well as the rim, is split; 9, a longitudinal groove in each side of the exterior of the hub in the plane of the joint-cracks in the hub, these grooves extending as apertures through the web at the root of the pulleyarms, these grooves therefore cutting largely through the wall of the hub and leaving standing only thin interior portions at the bore-of the hub, small portions being left standing at the outer portion of the roots of the arms, these grooves being cored so deeply, except at the extreme ends of the hub, that when the hub is bored the grooves result in slots in the hub,except at the ends of the hub; l0,bolts engaging holes in lugs 8 and serving as clampingbolts for the hub; 11, the bushings, the same being much shorter than the hub of the pulley and employed in duplicate,one bushingbeing disposed at each end of the pulley-hub, these bushings-being also split; 12, exterior flanges at each end of each bushing, these flanges 'being accurately turned to fit the bore of the pulley, the exterior of the body of the bushing between the flanges being somewhat less than the bore of the pulley; 13, slots formed serving to divide the halves from each other,

except at small end portions at the outer part of flanges 12; 14, trunnions projecting outwardly from the central portion of the periphthe bushing-halves; 16, an eccentric chamber forming an enlargement of the bore of onehalf of each bushing; 17, a roller disposed in each chamber 16, parallel withthe axis of the bushing, and having such diameter as to nearly fill the space between the shaft and the bore of chamber 16, where that bore is the deepest; 18, flanges at the ends of chamber 16 in each bushing, these flanges confining roller 17 endwise, but loosely, and being bored concentric with the axis of the pulley; 19, the

shaft; 20, apertures cast in the hub of the pulley to loosely receive trunnions 14 of the bushings, these apertures being in the plane of the joint-crack of the hub of the pulley and formed half in each half of the hub at the joint-crack; and 21, apertures formed in the bore of the pulley to be loosely engaged by trunnions 15 of the bushings.

The improved pulley without its bushings is to be integrally cast and then bored and turned, after which the pulley is to be cracked into two halves by the use of drifts or other suitable implements in the grooves 9 at the hub and in the grooves formed between the ribs at the rim. The groove formed between ribs et nicely guides the rim crack free from the influence of lugs 5 and leaves the cracked rim-joint the full thickness of the rim. Bolts 6 and 10 are then to be applied, thus securing the two halves of the pulley together with the fractured surfaces interlocking. Bolts 6 are near each edge of the rim and away from the pulley-arms and make the rim-joint tight and permanent, there being an absence of the chafing usually found in split pulleys constructedon this general principle.

The pulley may, if desired, instead of being bored and turned before it is broken in two, be bored and turned after it is broken in two and the halves reunited by the bolts. In either case it will be found that the bolting brings practically no distorting strains upon the pulley-rim.

If desired, the pulley may be employed as a solid pulley without being broken in two, in which case its construction permits of its being broken in two at any future time when it be desired to employ the pulley as a split pulley.

The bushings are each cast integrally, after which they are bored and then turned at flanges 12 to accurately fit the pulley, after which they are broken in two by means of a drift inserted in slots 13. The bushings are then to be disposed in the ends of the bore of the hub of the pulley, trunnions 1e lying in apertures 20 and trunnions 15 engaging apertures 21. The trunnions prevent anypossible rotation of the bushings within the pulleyhub, and for many conditions either pair of trunnions 14 or 15 may be omitted. As an article of manufacture it is preferable that the bushings be not broken in two until the occasion for their use arises, this plan for the time being reducing the number of pieces to be dealt with. \Vhen the pulley, with its bushings, is to be applied to a shaft, the roller 17 is laid in the chamber 16 and the pulley and bushing put upon the shaft. The turning of the pulley a trifle in either direction with reference to the shaft causes the roller to be pinched between the shaft and the wall of the chamber, the pulley thus being prevented from further rotation with reference to the shaft and being thus securely held in place upon the shaft.

It is obvious that the pulley or the pulley with its bushings is adapted to be secured to its shaft by any of the usual means, such as a set-screw or key. Vhere it is desired to employ the pulley or the pulley with its bushings on a shaft upon which it is to be held by clamping friction alone, then in that case it is preferable that the contiguous surfaces at the joint-cracks of the pulley-hub and bushings should be cut away, so as to give clampin g clearance. \Vhen the pulley is thus used upon a shaft by which it is held by clamping friction alone, the disposition of the short bushings at the ends of the pulley-hub give a certain degree of independence and elasticity to the clamping system, thus permitting the pulley to be more readily clamped to a shaft which is not truly uniform in diameter or which has become roughened or burred.

If the cores employed in forming grooves 9 cut through into the bore of the hub, as cast, it would be practically impossible to set the cores, it being requisite that some distance be left between the core forming the bore and the core forming the grooves. Grooves 9 may therefore be bored of such depth as not to cut through to the central bore, the remaining metal being, however, so thin that when the pulley-hub is bored this thin metal will be cut away, thus leaving slots in the sides of the hub extending nearly from end to end and leaving also open the apertures 20.

I claim as my invention 1. In a split pulley, the combination, substantially as set forth, of a divided rim and hub with the uniting pulley-arms forming two pulley-halves, lugs and bolts uniting said pulley-halves, and a pair of ribs projecting inwardly from the rim at each joint-crack therein, the inner faces of said ribs being angularly disposed with reference to each other to form a V-shaped groove whose root is at the inner surface of the pulley-rim at the jointcrack, said rim having normal thickness at the roots of said grooves.

2. In a split pulley, the combination, substantially as set forth, of a divided rim and hub having the rim united to the hub by arms, lugs and bolts at the hub for clamping the hub-halves together, a pair of separated lugs projecting inwardly from the rim at each edge thereof near the ends of the joint-cracks in the rim, the separations between the two lugs of each pair straddling the j oint-cracks of the rim, and the two pairs of lugs ateach jointcrack being disconnected from each other, the rim having full normal thickness between the two pairs of lugs at each joint-crack, perforated bosses projecting inwardly from the inner faces of said lugs into contact with each other, and clamp-bolts passing through said lugs and perforated bosses.

3. In a split pulley, the combination, substantially as set forth, of a rim, a hub, arms uniting the hub and rim and uniting with each other by a web at the root of the arms, there being longitudinal grooves at opposite sides of the hub and extending as apertures through said web at the root of the arms, portions of said web forming outer walls for said apertures, and bolts and lugs for uniting the pulley-halves when the pulley is broken in two.

4. In a split pulley, the combination, substantially as set forth, of a rim, a hub, and arms uniting said hub, said hub being provided with longitudinal grooves at opposite sides and extending-from end to end of the hub, the central portion of said grooves being deepened toform slots extending through the wall of the hub and into the bored-hubhole of the pulley, said grooves being shallower at the ends of the hub, and lugs and bolts at the rim and hub for uniting the pulley-halves. after the pulley is broken in two.

5. In a split pulley, the combination, substantially as set forth, of a divided rim and divided cylindrically-bored hub, lugs and bolts for uniting the pulley-halves,and abored bushing having a cylindrical body smaller than the bore of said hub and having at each end a flange concentric with the bore of the bushing-and fitting within the bore of the pulley.

6. In a split pulley, the combination, substantially as set forth, of a divided rim and divided cylindricallybored hub provided with apertures in its wall, lugs and bolts for uniting the pulley-halves, a bored bushing having its exterior cylindrical to fit the bore of the hub, and trunnions extending from the periphery of the bushing into engagement with the said apertures in the bore of the pulley.

7. In a split pulley, the combination, substantially as set forth, of a divided rim and hub, lugs and bolts for uniting the pulleyhalves, and a bored bushing having exterior portions fitting the bore of the pulley and provided with longitudinal slots extending nearly from end to end of the bushing and through the wall of the bushing, the wall of the bushing being continuous at the unslottedends thereof.

8. In a pulley, the combination, substantially as set forth, of a rim, a hub provided with a bore concentric with said rim and provided at each end with a chamber eccentric to said bore, and a roller disposed longitudinally Within each of said chambers and adapted to engage between a shaft and the walls of said chambers.

JOHN E. DONOVAN.

Witnesses:

CLEMENT BATES, J 08. L. MEYER. 

